xref: /openbsd-src/sbin/swapctl/swapctl.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c) 
1 /*	$OpenBSD: swapctl.c,v 1.23 2016/03/17 19:40:43 krw Exp $	*/
2 /*	$NetBSD: swapctl.c,v 1.9 1998/07/26 20:23:15 mycroft Exp $	*/
3 
4 /*
5  * Copyright (c) 1996, 1997 Matthew R. Green
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * swapctl command:
34  *	-A		add all devices listed as `sw' in /etc/fstab
35  *	-t [blk|noblk]	if -A, add either all block device or all non-block
36  *			devices
37  *	-a <path>	add this device
38  *	-d <path>	remove this swap device
39  *	-l		list swap devices
40  *	-s		short listing of swap devices
41  *	-k		use kilobytes
42  *	-p <pri>	use this priority
43  *	-c <path>	change priority
44  *
45  * or, if invoked as "swapon" (compatibility mode):
46  *
47  *	-a		all devices listed as `sw' in /etc/fstab
48  *	-t		same as -t above (feature not present in old
49  *			swapon(8) command)
50  *	<dev>		add this device
51  */
52 
53 #include <sys/stat.h>
54 #include <sys/swap.h>
55 #include <sys/wait.h>
56 
57 #include <unistd.h>
58 #include <err.h>
59 #include <errno.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <limits.h>
63 #include <string.h>
64 #include <fstab.h>
65 #include <util.h>
66 
67 #include "swapctl.h"
68 
69 int	command;
70 
71 /*
72  * Commands for swapctl(8).  These are mutually exclusive.
73  */
74 #define	CMD_A		0x01	/* process /etc/fstab */
75 #define	CMD_a		0x02	/* add a swap file/device */
76 #define	CMD_c		0x04	/* change priority of a swap file/device */
77 #define	CMD_d		0x08	/* delete a swap file/device */
78 #define	CMD_l		0x10	/* list swap files/devices */
79 #define	CMD_s		0x20	/* summary of swap files/devices */
80 
81 #define	SET_COMMAND(cmd) \
82 do { \
83 	if (command) \
84 		usage(); \
85 	command = (cmd); \
86 } while (0)
87 
88 /*
89  * Commands that require a "path" argument at the end of the command
90  * line, and the ones which require that none exist.
91  */
92 #define	REQUIRE_PATH	(CMD_a | CMD_c | CMD_d)
93 #define	REQUIRE_NOPATH	(CMD_A | CMD_l | CMD_s)
94 
95 /*
96  * Option flags, and the commands with which they are valid.
97  */
98 int	kflag;		/* display in 1K blocks */
99 #define	KFLAG_CMDS	(CMD_l | CMD_s)
100 
101 int	pflag;		/* priority was specified */
102 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
103 
104 char	*tflag;		/* swap device type (blk or noblk) */
105 #define	TFLAG_CMDS	(CMD_A)
106 
107 int	pri;		/* uses 0 as default pri */
108 
109 static	void change_priority(char *);
110 static	void add_swap(char *);
111 static	void del_swap(char *);
112 static	void do_fstab(void);
113 static	void usage(void);
114 static	int  swapon_command(int, char **);
115 
116 extern	char *__progname;	/* from crt0.o */
117 
118 int
119 main(int argc, char *argv[])
120 {
121 	const char *errstr;
122 	int	c;
123 
124 	if (strcmp(__progname, "swapon") == 0)
125 		return swapon_command(argc, argv);
126 
127 	while ((c = getopt(argc, argv, "Aacdlkp:st:")) != -1) {
128 		switch (c) {
129 		case 'A':
130 			SET_COMMAND(CMD_A);
131 			break;
132 
133 		case 'a':
134 			SET_COMMAND(CMD_a);
135 			break;
136 
137 		case 'c':
138 			SET_COMMAND(CMD_c);
139 			break;
140 
141 		case 'd':
142 			SET_COMMAND(CMD_d);
143 			break;
144 
145 		case 'l':
146 			SET_COMMAND(CMD_l);
147 			break;
148 
149 		case 'k':
150 			kflag = 1;
151 			break;
152 
153 		case 'p':
154 			pflag = 1;
155 			pri = strtonum(optarg, 0, INT_MAX, &errstr);
156 			if (errstr)
157 				errx(1, "-p %s: %s", errstr, optarg);
158 			break;
159 
160 		case 's':
161 			SET_COMMAND(CMD_s);
162 			break;
163 
164 		case 't':
165 			if (tflag != NULL)
166 				usage();
167 			tflag = optarg;
168 			break;
169 
170 		default:
171 			usage();
172 			/* NOTREACHED */
173 		}
174 	}
175 
176 	argv += optind;
177 	argc -= optind;
178 
179 	/* Did the user specify a command? */
180 	if (command == 0) {
181 		if (argc == 0)
182 			SET_COMMAND(CMD_l);
183 		else
184 			usage();
185 	}
186 
187 	switch (argc) {
188 	case 0:
189 		if (command & REQUIRE_PATH)
190 			usage();
191 		break;
192 
193 	case 1:
194 		if (command & REQUIRE_NOPATH)
195 			usage();
196 		break;
197 
198 	default:
199 		usage();
200 	}
201 
202 	/* To change priority, you have to specify one. */
203 	if ((command == CMD_c) && pflag == 0)
204 		usage();
205 
206 	/* Sanity-check -t */
207 	if (tflag != NULL) {
208 		if (command != CMD_A)
209 			usage();
210 		if (strcmp(tflag, "blk") != 0 &&
211 		    strcmp(tflag, "noblk") != 0)
212 			usage();
213 	}
214 
215 	/* Dispatch the command. */
216 	switch (command) {
217 	case CMD_l:
218 		list_swap(pri, kflag, pflag, 1);
219 		break;
220 
221 	case CMD_s:
222 		list_swap(pri, kflag, pflag, 0);
223 		break;
224 
225 	case CMD_c:
226 		change_priority(argv[0]);
227 		break;
228 
229 	case CMD_a:
230 		add_swap(argv[0]);
231 		break;
232 
233 	case CMD_d:
234 		del_swap(argv[0]);
235 		break;
236 
237 	case CMD_A:
238 		do_fstab();
239 		break;
240 	}
241 
242 	return (0);
243 }
244 
245 /*
246  * swapon_command: emulate the old swapon(8) program.
247  */
248 int
249 swapon_command(int argc, char **argv)
250 {
251 	int ch, fiztab = 0;
252 
253 	while ((ch = getopt(argc, argv, "at:")) != -1) {
254 		switch (ch) {
255 		case 'a':
256 			fiztab = 1;
257 			break;
258 		case 't':
259 			if (tflag != NULL)
260 				usage();
261 			tflag = optarg;
262 			break;
263 		default:
264 			goto swapon_usage;
265 		}
266 	}
267 	argc -= optind;
268 	argv += optind;
269 
270 	if (fiztab) {
271 		if (argc)
272 			goto swapon_usage;
273 		/* Sanity-check -t */
274 		if (tflag != NULL) {
275 			if (strcmp(tflag, "blk") != 0 &&
276 			    strcmp(tflag, "noblk") != 0)
277 				usage();
278 		}
279 		do_fstab();
280 		return (0);
281 	} else if (argc == 0 || tflag != NULL)
282 		goto swapon_usage;
283 
284 	while (argc) {
285 		add_swap(argv[0]);
286 		argc--;
287 		argv++;
288 	}
289 	return (0);
290 
291  swapon_usage:
292 	fprintf(stderr, "usage: %s -a | path\n", __progname);
293 	return (1);
294 }
295 
296 /*
297  * change_priority:  change the priority of a swap device.
298  */
299 void
300 change_priority(char *path)
301 {
302 
303 	if (swapctl(SWAP_CTL, path, pri) < 0)
304 		warn("%s", path);
305 }
306 
307 /*
308  * add_swap:  add the pathname to the list of swap devices.
309  */
310 void
311 add_swap(char *path)
312 {
313 
314 	if (swapctl(SWAP_ON, path, pri) < 0)
315 		if (errno != EBUSY)
316 			err(1, "%s", path);
317 }
318 
319 /*
320  * del_swap:  remove the pathname from the list of swap devices.
321  */
322 void
323 del_swap(char *path)
324 {
325 
326 	if (swapctl(SWAP_OFF, path, pri) < 0)
327 		err(1, "%s", path);
328 }
329 
330 void
331 do_fstab(void)
332 {
333 	struct	fstab *fp;
334 	char	*s;
335 	long	priority;
336 	struct	stat st;
337 	mode_t	rejecttype;
338 	int	gotone = 0;
339 
340 	/*
341 	 * Select which mount point types to reject, depending on the
342 	 * value of the -t parameter.
343 	 */
344 	if (tflag != NULL) {
345 		if (strcmp(tflag, "blk") == 0)
346 			rejecttype = S_IFREG;
347 		else if (strcmp(tflag, "noblk") == 0)
348 			rejecttype = S_IFBLK;
349 	} else
350 		rejecttype = 0;
351 
352 #define PRIORITYEQ	"priority="
353 #define NFSMNTPT	"nfsmntpt="
354 #define PATH_MOUNT	"/sbin/mount_nfs"
355 	while ((fp = getfsent()) != NULL) {
356 		const char *spec;
357 
358 		if (strcmp(fp->fs_type, "sw") != 0)
359 			continue;
360 
361 		spec = fp->fs_spec;
362 
363 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
364 			s += sizeof(PRIORITYEQ) - 1;
365 			priority = atol(s);
366 		} else
367 			priority = pri;
368 
369 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
370 			char *t;
371 			pid_t pid;
372 			int status;
373 
374 			/*
375 			 * Skip this song and dance if we're only
376 			 * doing block devices.
377 			 */
378 			if (rejecttype == S_IFREG)
379 				continue;
380 
381 			t = strpbrk(s, ",");
382 			if (t != 0)
383 				*t = '\0';
384 			spec = strdup(s + strlen(NFSMNTPT));
385 			if (spec == NULL)
386 				err(1, "strdup");
387 
388 			if (t != 0)
389 				*t = ',';
390 
391 			if (strlen(spec) == 0) {
392 				warnx("empty mountpoint");
393 				free((char *)spec);
394 				continue;
395 			}
396 
397 			switch (pid = vfork()) {
398 			case -1:	/* error */
399 				err(1, "vfork");
400 			case 0:
401 				execl(PATH_MOUNT, PATH_MOUNT, fp->fs_spec, spec,
402 				    (char *)NULL);
403 				err(1, "execl");
404 			}
405 			while (waitpid(pid, &status, 0) < 0)
406 				if (errno != EINTR)
407 					err(1, "waitpid");
408 			if (status != 0) {
409 				warnx("%s: mount failed", fp->fs_spec);
410 				free((char *)spec);
411 				continue;
412 			}
413 		} else if (isduid(spec, 0)) {
414 			if (rejecttype == S_IFBLK)
415 				continue;
416 		} else {
417 			/*
418 			 * Determine blk-ness.  Don't even consider a
419 			 * mountpoint outside /dev as a block device.
420 			 */
421 			if (rejecttype == S_IFREG) {
422 				if (strncmp("/dev/", spec, 5) != 0)
423 					continue;
424 			}
425 			if (stat(spec, &st) < 0) {
426 				warn("%s", spec);
427 				continue;
428 			}
429 			if ((st.st_mode & S_IFMT) == rejecttype)
430 				continue;
431 
432 			/*
433 			 * Do not allow fancy objects to be swap areas.
434 			 */
435 			if (!S_ISREG(st.st_mode) &&
436 			    !S_ISBLK(st.st_mode))
437 				continue;
438 		}
439 
440 		if (swapctl(SWAP_ON, spec, (int)priority) < 0) {
441 			if (errno != EBUSY)
442 				warn("%s", spec);
443 		} else {
444 			gotone = 1;
445 			printf("%s: adding %s as swap device at priority %d\n",
446 			    __progname, fp->fs_spec, (int)priority);
447 		}
448 
449 		if (spec != fp->fs_spec)
450 			free((char *)spec);
451 	}
452 	if (gotone == 0)
453 		exit(1);
454 }
455 
456 void
457 usage(void)
458 {
459 
460 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk | noblk]\n",
461 	    __progname);
462 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
463 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
464 	fprintf(stderr, "       %s -d path\n", __progname);
465 	fprintf(stderr, "       %s [[-l] | -s] [-k]\n", __progname);
466 	exit(1);
467 }
468